I had to look things up, but once i found an example of numbers notation on the 5 bead variant i can see what you mean. Effectively you have something akin to

I had to look things up, but once i found an example of numbers notation on the 5 bead variant i can see what you mean. Effectively you have something akin to a binary watch, where you move the top bead to indicate if the bottom 4 beads are 0 to 4 or 5 to 9.